From: Tobias Geerinckx-Rice <me@tobias.gr>
Date: Thu, 13 Aug 2020 15:21:30 +0200
Subject: [PATCH] gnu: opencv: Fix build with Jasper 2.0.19.

Taken verbatim from upstream: <https://github.com/opencv/opencv/issues/17984>.

From f66fc199a20882c546fa31142e9c0f5a8b3cf983 Mon Sep 17 00:00:00 2001
From: Florian Jung <flo@windfis.ch>
Date: Wed, 29 Jul 2020 18:51:55 +0200
Subject: [PATCH] Fix build of grfmt_jpeg2000.cpp

libjasper has recently changed `jas_matrix_get` from a macro to an inline function
(389951d071 in https://github.com/jasper-software/jasper), causing the build to fail.
---
 modules/imgcodecs/src/grfmt_jpeg2000.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/modules/imgcodecs/src/grfmt_jpeg2000.cpp b/modules/imgcodecs/src/grfmt_jpeg2000.cpp
index fe69f80c86f..0f4d28d6f4d 100644
--- a/modules/imgcodecs/src/grfmt_jpeg2000.cpp
+++ b/modules/imgcodecs/src/grfmt_jpeg2000.cpp
@@ -377,7 +377,7 @@ bool  Jpeg2KDecoder::readComponent8u( uchar *data, void *_buffer,
 
     for( y = 0; y < yend - ystart; )
     {
-        jas_seqent_t* pix_row = &jas_matrix_get( buffer, y / ystep, 0 );
+        jas_seqent_t* pix_row = jas_matrix_getref( buffer, y / ystep, 0 );
         uchar* dst = data + (y - yoffset) * step - xoffset;
 
         if( xstep == 1 )
@@ -443,7 +443,7 @@ bool  Jpeg2KDecoder::readComponent16u( unsigned short *data, void *_buffer,
 
     for( y = 0; y < yend - ystart; )
     {
-        jas_seqent_t* pix_row = &jas_matrix_get( buffer, y / ystep, 0 );
+        jas_seqent_t* pix_row = jas_matrix_getref( buffer, y / ystep, 0 );
         ushort* dst = data + (y - yoffset) * step - xoffset;
 
         if( xstep == 1 )
